ON THE CHANGE OF COLOUR IN BIRDS. 83 
A. Entire, to all or most of the small feathers, and in some 
cases also to the two middle tail- and three inner wing- 
quills, as, for instance with— 
Anthus Hematopus 
Motacilla Charadrius 
Saxicola rubetra Anas glacialis 
Sylvia cinerea Sterna 
Muscicapa collaris Larus 
_ atricapilla Lestris 
Tringa Procellaria 
Phalaropus Colymbus 
Totanus Uria 
Limosa Mormon 
Strepsilas Alca 
s. Partial, affecting only some of the feathers of the head and 
neck, as with Sylvia suecica, Emberiza nivalis and 
lapponica, Vanellus cristatus, and also with a large 
number of the younger males. (particularly of Linné’s 
Passeres), the first spring after the year of their birth. 
III. Summer Moult.—Takes place after the pairing season, 
and is— 
a. Entire: in which case all the small feathers are changed, 
and in some cases (e.g. Anas boschas) the four middle 
tail- and five or six inner wing-quills. The males then 
adopt a plumage which more or less resembles that of 
the female; as in the Ducks (excepting tadorna and 
glacialis) ; thus Anas boschas, acuta, penelope, clypeata, 
querquedula, crecca, Fuligula cristata, ferina, clangula, 
mollissima,* Mergus, and others. 
n. Partial; in which case the head and neck feathers are 
exchanged for short, narrow and soft feathers, which 
almost resemble the immature plumage of the bird; and 
* The Eider-drake undergoes, from the middle of June till the commencement 
of October, an almost uninterrupted change of plumage, at least on the breast; for 
the reddish breast-feathers are at first succeeded by almost pure brown ones; then 
similar ones with more or less white in the centre; then reddish ones with a black 
border; and, lastly, the reddish winter feathers again. Drakes shot in September 
often show three sorts of these feathers, of which two certainly have blood-quills. 
_ No bird therefore affords better opportunities than this for a study of the change of 
colour by a real moult, 
